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authorSamuel Thibault <samuel.thibault@ens-lyon.org>2020-06-06 20:21:22 +0200
committerSamuel Thibault <samuel.thibault@ens-lyon.org>2020-06-06 20:24:30 +0200
commit02937d825a71636c13b3f4229e5d6c9e54e327d5 (patch)
tree822a53b962bde8520f69daf62d8a0d62967a16a1
parenthurd: Add pointer guard support (diff)
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hurd: fix clearing SS_ONSTACK when longjmp-ing from sighandler
* sysdeps/i386/htl/Makefile: New file. * sysdeps/i386/htl/tcb-offsets.sym: New file. * sysdeps/mach/hurd/i386/Makefile [setjmp] (gen-as-const-headers): Add signal-defines.sym. * sysdeps/mach/hurd/i386/____longjmp_chk.S: Include tcb-offsets.h. (____longjmp_chk): Harmonize with i386's __longjmp. Clear SS_ONSTACK when jumping off the alternate stack. * sysdeps/mach/hurd/i386/__longjmp.S: New file.
-rw-r--r--sysdeps/i386/htl/Makefile20
-rw-r--r--sysdeps/i386/htl/tcb-offsets.sym8
-rw-r--r--sysdeps/mach/hurd/i386/Makefile4
-rw-r--r--sysdeps/mach/hurd/i386/____longjmp_chk.S70
-rw-r--r--sysdeps/mach/hurd/i386/__longjmp.S84
5 files changed, 154 insertions, 32 deletions
diff --git a/sysdeps/i386/htl/Makefile b/sysdeps/i386/htl/Makefile
new file mode 100644
index 0000000000..8573ce6990
--- /dev/null
+++ b/sysdeps/i386/htl/Makefile
@@ -0,0 +1,20 @@
+# Copyright (C) 2020 Free Software Foundation, Inc.
+# This file is part of the GNU C Library.
+
+# The GNU C Library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or (at your option) any later version.
+
+# The GNU C Library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+# Lesser General Public License for more details.
+
+# You should have received a copy of the GNU Lesser General Public
+# License along with the GNU C Library; if not, see
+# <https://www.gnu.org/licenses/>.
+
+ifeq ($(subdir),csu)
+gen-as-const-headers += tcb-offsets.sym
+endif
diff --git a/sysdeps/i386/htl/tcb-offsets.sym b/sysdeps/i386/htl/tcb-offsets.sym
new file mode 100644
index 0000000000..7b7c719369
--- /dev/null
+++ b/sysdeps/i386/htl/tcb-offsets.sym
@@ -0,0 +1,8 @@
+#include <sysdep.h>
+#include <tls.h>
+#include <kernel-features.h>
+
+MULTIPLE_THREADS_OFFSET offsetof (tcbhead_t, multiple_threads)
+SYSINFO_OFFSET offsetof (tcbhead_t, sysinfo)
+POINTER_GUARD offsetof (tcbhead_t, pointer_guard)
+SIGSTATE_OFFSET offsetof (tcbhead_t, _hurd_sigstate)
diff --git a/sysdeps/mach/hurd/i386/Makefile b/sysdeps/mach/hurd/i386/Makefile
index 068f7d0419..495b927b82 100644
--- a/sysdeps/mach/hurd/i386/Makefile
+++ b/sysdeps/mach/hurd/i386/Makefile
@@ -7,6 +7,10 @@ ifeq ($(subdir),debug)
gen-as-const-headers += signal-defines.sym
endif
+ifeq ($(subdir),setjmp)
+gen-as-const-headers += signal-defines.sym
+endif
+
ifeq ($(subdir),csu)
ifeq (yes,$(build-shared))
sysdep_routines += divdi3
diff --git a/sysdeps/mach/hurd/i386/____longjmp_chk.S b/sysdeps/mach/hurd/i386/____longjmp_chk.S
index 819e5dc875..4d3a331728 100644
--- a/sysdeps/mach/hurd/i386/____longjmp_chk.S
+++ b/sysdeps/mach/hurd/i386/____longjmp_chk.S
@@ -17,6 +17,7 @@
#include <sysdep.h>
#include <jmpbuf-offsets.h>
+#include <tcb-offsets.h>
#include <asm-syntax.h>
#include <signal-defines.h>
@@ -47,65 +48,70 @@ longjmp_msg:
.text
ENTRY (____longjmp_chk)
- movl 4(%esp), %ecx /* User's jmp_buf in %ecx. */
+ movl 4(%esp), %eax /* User's jmp_buf in %eax. */
/* Save the return address now. */
- movl (JB_PC*4)(%ecx), %edx
+ movl (JB_PC*4)(%eax), %edx
/* Get the stack pointer. */
- movl (JB_SP*4)(%ecx), %edi
- cfi_undefined(%edi)
+ movl (JB_SP*4)(%eax), %ecx
+ cfi_undefined(%ecx)
#ifdef PTR_DEMANGLE
PTR_DEMANGLE (%edx)
- PTR_DEMANGLE (%edi)
+ PTR_DEMANGLE (%ecx)
#endif
- cmpl %edi, %esp
+ movl %gs:SIGSTATE_OFFSET,%edi
+
+ testl $SS_ONSTACK, (HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_FLAGS__OFFSET)(%edi)
+ jnz .Lonstack
+
+ /* We were on the main stack */
+
+ cmpl %ecx, %esp
/* Jumping to a higher-address frame is always allowed. */
jbe .Lok
- /* Passing here, we're either about to do something invalid, or we're
- executing on an alternative signal stack. */
+ /* Otherwise it's not allowed. */
+ CALL_FAIL
- /* TODO: need locking? */
- /* struct hurd_sigstate * _hurd_self_sigstate (void) */
- call HIDDEN_JUMPTARGET(_hurd_self_sigstate)
- /* TODO: %eax and %eax->sigaltstack are always valid? */
+.Lonstack:
+ /* We were on the alternate stack, can't really easily check anything
+ since longjmp may get us out of the alternate stack. */
- testl $SS_ONSTACK, (HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_FLAGS__OFFSET)(%eax)
- /* Fail if SS_ONSTACK is not set. */
- jz .Lfail
+ cmpl (HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_SP__OFFSET)(%edi), %ecx
+ jb .Loks /* We jump below the alternate stack, switch. */
- movl (HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_SP__OFFSET)(%eax), %ebx
- addl (HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_SIZE__OFFSET)(%eax), %ebx
- subl %edi, %ebx
- cmpl (HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_SIZE__OFFSET)(%eax), %ebx
- /* TODO: comment this calculation. */
- jae .Lok
+ movl (HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_SP__OFFSET)(%edi), %ebx
+ addl (HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_SIZE__OFFSET)(%edi), %ebx
+ cmpl %ebx, %ecx
+ jb .Lok /* We jump inside the alternate stack, do not switch. */
-.Lfail: CALL_FAIL
+ /* We jump above the alternate stack, switch. */
+
+.Loks: /* We jump out of the alternate stack, clear SS_ONSTACK flag. */
+ andl $~(SS_ONSTACK), (HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_FLAGS__OFFSET)(%edi)
.Lok: /* We add unwind information for the target here. */
- cfi_def_cfa(%ecx, 0)
+ cfi_def_cfa(%eax, 0)
cfi_register(%eip, %edx)
- cfi_register(%esp, %edi)
+ cfi_register(%esp, %ecx)
cfi_offset(%ebx, JB_BX*4)
cfi_offset(%esi, JB_SI*4)
cfi_offset(%edi, JB_DI*4)
cfi_offset(%ebp, JB_BP*4)
-
- movl 8(%esp), %eax /* Second argument is return value. */
- movl %edi, %esp
-
/* Restore registers. */
- movl (JB_BX*4)(%ecx), %ebx
- movl (JB_SI*4)(%ecx), %esi
- movl (JB_DI*4)(%ecx), %edi
- movl (JB_BP*4)(%ecx), %ebp
+ movl (JB_BX*4)(%eax), %ebx
+ movl (JB_SI*4)(%eax), %esi
+ movl (JB_DI*4)(%eax), %edi
+ movl (JB_BP*4)(%eax), %ebp
cfi_restore(%ebx)
cfi_restore(%esi)
cfi_restore(%edi)
cfi_restore(%ebp)
+ movl 8(%esp), %eax /* Second argument is return value. */
+ movl %ecx, %esp
+
/* Jump to saved PC. */
jmp *%edx
END (____longjmp_chk)
diff --git a/sysdeps/mach/hurd/i386/__longjmp.S b/sysdeps/mach/hurd/i386/__longjmp.S
new file mode 100644
index 0000000000..d123c214c9
--- /dev/null
+++ b/sysdeps/mach/hurd/i386/__longjmp.S
@@ -0,0 +1,84 @@
+/* Copyright (C) 2001-2020 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+#include <sysdep.h>
+#include <jmpbuf-offsets.h>
+#include <tcb-offsets.h>
+#include <asm-syntax.h>
+
+#include <signal-defines.h>
+/* #include <signal.h> */
+#define SS_ONSTACK 1
+
+ .text
+ENTRY (__longjmp)
+ movl 4(%esp), %eax /* User's jmp_buf in %eax. */
+
+ /* Save the return address now. */
+ movl (JB_PC*4)(%eax), %edx
+ /* Get the stack pointer. */
+ movl (JB_SP*4)(%eax), %ecx
+ cfi_undefined(%ecx)
+#ifdef PTR_DEMANGLE
+ PTR_DEMANGLE (%edx)
+ PTR_DEMANGLE (%ecx)
+#endif
+
+ movl %gs:SIGSTATE_OFFSET,%edi
+
+ testl $SS_ONSTACK, (HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_FLAGS__OFFSET)(%edi)
+ jz .Lok
+
+ /* We were on the alternate stack. */
+
+ cmpl (HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_SP__OFFSET)(%edi), %ecx
+ jb .Loks /* We jump below the alternate stack, switch. */
+
+ movl (HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_SP__OFFSET)(%edi), %ebx
+ addl (HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_SIZE__OFFSET)(%edi), %ebx
+ cmpl %ebx, %ecx
+ jb .Lok /* We jump inside the alternate stack, do not switch. */
+
+ /* We jump above the alternate stack, switch. */
+
+.Loks: /* We jump out of the alternate stack, clear SS_ONSTACK flag. */
+ andl $~(SS_ONSTACK), (HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_FLAGS__OFFSET)(%edi)
+
+.Lok: /* We add unwind information for the target here. */
+ cfi_def_cfa(%eax, 0)
+ cfi_register(%eip, %edx)
+ cfi_register(%esp, %ecx)
+ cfi_offset(%ebx, JB_BX*4)
+ cfi_offset(%esi, JB_SI*4)
+ cfi_offset(%edi, JB_DI*4)
+ cfi_offset(%ebp, JB_BP*4)
+ /* Restore registers. */
+ movl (JB_BX*4)(%eax), %ebx
+ movl (JB_SI*4)(%eax), %esi
+ movl (JB_DI*4)(%eax), %edi
+ movl (JB_BP*4)(%eax), %ebp
+ cfi_restore(%ebx)
+ cfi_restore(%esi)
+ cfi_restore(%edi)
+ cfi_restore(%ebp)
+
+ movl 8(%esp), %eax /* Second argument is return value. */
+ movl %ecx, %esp
+
+ /* Jump to saved PC. */
+ jmp *%edx
+END (__longjmp)